1. Field of the Invention
The present invention relates to cord retractor mechanisms and more particularly concerns a mechanism that can be attached to any position along the length of a cord without requiring splicing, pre-coiled wires or brush commutators.
2. Description of Related Art
Various types of electronic instrumentation are remotely controlled or are coupled with a handset or hand-held controller by an multi-wire electric cord extending to some type of electronic box. For example, a telephone handset or a hand-held microphone and control are connected by multi-wire electric cords to relatively fixedly positioned electronic devices, such as the telephone body or a recorder itself. A hand controller or handset for an aircraft passenger entertainment system may be connected by an electric cable to an electronic control box. The handset, which is preferably stored in a position closer to the electronic control box, is movable to different locations for operation and, accordingly, it is necessary that the length of electrical cable connecting the handset with the electronic control box have a variable effective length.
Many mechanisms have been devised for facilitating variation in the effective length of the cord connected to a handset. These include wires pre-formed in a coil or spiral configuration, which may provide a shorter length of interconnecting cord, but, nevertheless, still allow a length of loose wire to extend from the handset.
A common retractor mechanism actually winds the cord around a drum or axle for storage and allows lengths of cord to be withdrawn by rotation of the drum. Since the end of the cord within the storage device must be connected to a fixed cord, which itself is connected to the electronic control box, brush commutators are required to provide electrical continuity between the fixed cord section and the rotating cord section. Such brush commutators are relatively complex, difficult to manufacture, and, importantly, lack reliability. Brushes are notoriously short lived. They wear rapidly and must be replaced after a relatively short period of use. Moreover, the cord coiling mechanism can be connected at only one position along the length of the cord and must be used with a cord having a splice or connecting brushes. Some cord retractors operate through twisting of the cord, which causes repetitive stresses, resulting in premature breakage of the cord wires.
Accordingly, it is an object of the present invention to provide a cord retractor that avoids or minimizes above-mentioned problems.